Note 2 - Stock-Based Compensation (Detail) - 2004 Employee Stock Purchase Plan Fair Value Assumptions (Two Thousand Four Employee Stock Purchase Plan [Member])	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Two Thousand Four Employee Stock Purchase Plan [Member]
Expected term (years)	6 months	6 months	6 months	6 months
Expected volatility	39.60%	40.90%	45.80%	39.20%
Risk-free interest rate	0.10%	0.10%	0.10%	0.10%
Dividend yield	0.00%	0.00%	0.00%	0.00%